On Fri, Nov 20, 2015 at 06:35:48PM -0500, James Simmons wrote:
> +int libcfs_ioctl_getdata_len(const struct libcfs_ioctl_hdr __user *arg,
> + __u32 *len)
> +{
> + struct libcfs_ioctl_hdr hdr;
>
> - orig_len = hdr->ioc_len;
> - if (copy_from_user(buf, arg, hdr->ioc_len))
> + if (copy_from_user(&hdr, arg, sizeof(hdr)))
> return -EFAULT;
> - if (orig_len != data->ioc_len)
> - return -EINVAL;
This check was actually important. I don't see where it was moved to so
it looks like this patch introduces a serious information leak.
>
> - if (libcfs_ioctl_is_invalid(data)) {
> - CERROR("PORTALS: ioctl not correctly formatted\n");
> + if (hdr.ioc_version != LIBCFS_IOCTL_VERSION) {
> + CERROR("LNET: version mismatch expected %#x, got %#x\n",
> + LIBCFS_IOCTL_VERSION, hdr.ioc_version);
> return -EINVAL;
> }
>
> - if (data->ioc_inllen1)
> - data->ioc_inlbuf1 = &data->ioc_bulk[0];
> + *len = hdr.ioc_len;
>
> - if (data->ioc_inllen2)
> - data->ioc_inlbuf2 = &data->ioc_bulk[0] +
> - cfs_size_round(data->ioc_inllen1);
> + return 0;
> +}
>
> +int libcfs_ioctl_getdata(struct libcfs_ioctl_hdr *buf, __u32 buf_len,
> + const void __user *arg)
> +{
> + if (copy_from_user(buf, arg, buf_len))
> + return -EFAULT;
> return 0;
> }
Don't introduce this wrapper. Abstraction layers just make the code
harder to read and obscures bugs. Also the caller changes -EFAULT to
-EINVAL so right away it starts to be buggy.
>
> diff --git a/drivers/staging/lustre/lustre/libcfs/module.c
> b/drivers/staging/lustre/lustre/libcfs/module.c
> index 75247e9..5348699 100644
> --- a/drivers/staging/lustre/lustre/libcfs/module.c
> +++ b/drivers/staging/lustre/lustre/libcfs/module.c
> @@ -54,6 +54,8 @@
>
> # define DEBUG_SUBSYSTEM S_LNET
>
> +#define LIBCFS_MAX_IOCTL_BUF_LEN 2048
> +
> #include "../../include/linux/libcfs/libcfs.h"
> #include <asm/div64.h>
>
> @@ -241,11 +243,21 @@ int libcfs_deregister_ioctl(struct libcfs_ioctl_handler
> *hand)
> }
> EXPORT_SYMBOL(libcfs_deregister_ioctl);
>
> -static int libcfs_ioctl_int(struct cfs_psdev_file *pfile, unsigned long cmd,
> - void *arg, struct libcfs_ioctl_data *data)
> +static int libcfs_ioctl_handle(struct cfs_psdev_file *pfile, unsigned long
> cmd,
> + void *arg, struct libcfs_ioctl_hdr *hdr)
> {
> + struct libcfs_ioctl_data *data = NULL;
> int err = -EINVAL;
>
> + if ((cmd <= IOC_LIBCFS_LNETST) ||
> + (cmd >= IOC_LIBCFS_REGISTER_MYNID)) {
> + data = container_of(hdr, struct libcfs_ioctl_data, ioc_hdr);
> + err = libcfs_ioctl_data_adjust(data);
> + if (err != 0) {
Generally, remove pointless double negatives like this. It should be
just "if (err) " instead of "if (err != 0 != 0 != 0 != 0) " or whatever.
> + return err;
> + }
> + }
> +
> switch (cmd) {
> case IOC_LIBCFS_CLEAR_DEBUG:
> libcfs_debug_clear_buffer();
> @@ -280,11 +292,11 @@ static int libcfs_ioctl_int(struct cfs_psdev_file
> *pfile, unsigned long cmd,
> err = -EINVAL;
> down_read(&ioctl_list_sem);
> list_for_each_entry(hand, &ioctl_list, item) {
> - err = hand->handle_ioctl(cmd, data);
> + err = hand->handle_ioctl(cmd, hdr);
> if (err != -EINVAL) {
> if (err == 0)
> err = libcfs_ioctl_popdata(arg,
> - data, sizeof(*data));
> + hdr, hdr->ioc_len);
This variable has not been verified since the user wrote to it last so
here is the information leak.
regards,
dan carpenter
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